Stop 18: Uinta Mountains/Uinta Basin
This is an east-west mountain range. The Unita basin is a shallow basin extending to east central Utah. If we look at a cross section with Blue Mountain in the center, Blue Mtn is Paleozoic deposits with faults on each side. To the North are Precambrian layers. To the south are upturned layers of shallow lake bed deposits and Cenozoic layers further south. These end in the Roan Cliffs which are on top of the Book Cliffs. A north portion of Uinta are Jurassic rocks with almost vertical layers along narrow strips.
We continue on to Dinosaur National Monument which stretches from northeast Utah into Colorado.
Stop 19: Dinosaur National Monument
In 1909 Earl Douglass of the Carnegie Museum in Pittsburgh, Pennsylvania, found articulated dinosaur bones in Morrison layers. It was soon discovered that this was a mass burial site. At the entrance we see the Mancos Shale again, but between here and Green River they are buried. The sandstone hogbacks we see are underneath the Mancos. This is a mass accumulation site. The bones are not in levels like elsewhere. It is the Brushy Basin member, but in sandstone not mudstone. The sandstone indicates a vigorous river deposit.
To understand we look at a bend in the Green River here. There is sand on the inside of the bend, known as a point, and a cutbank on the outside of the bend. The deposit of sand is known as a “point bar.” It almost the same sand here as the Jurassic sand the bones are in. There are two bone producing horizons. 
This means there were two times when there were lots of dinosaurs dead on the sand. This relates to severe flood events that were several weeks long. The bones found were not abraded, so they were not transported far. The articulated bones here are not like the mass site at Cleveland-Lloyd Quarry. The flow direction of the deposit was from west to east. There would have been a “log jam” of dead dinosaurs on the pointbars. The most common bones here are sauropods with some therapods. After the flood the bones were buried. We don't know the exact age here because there are no ash layers to date, but it is a couple of million years younger than Cleveland-Lloyd because it is closer to the top of the Morrison Fm.
We take time to explore the quarry building, which still has bones in place as they were found.
We go into Vernal and visit the Utah Field House of Natural History.
http://www.stateparks.utah.gov/park_pages/field.htm
We go north on Highway 191 which goes through the upturned levels of layers from the 80 million year Mancos Fm at Vernal to the 1 billion year old Uinta Mountain Group at Flaming Gorge. We camp in the trees off the road in Wyoming.
The next day we head west on Interstate 80 and get to the Ruby Mountains in Nevada and camp by Angel Creek (dry). The next day we drive up to see Angel Lake with its waterfall and some of the oldest rocks in Nevada—Archean, at least 2.5 billion years old.
We arrive back in Rocklin having logged 2555 miles on our van. We'd replaced 7 tires on the three vehicles.
--Mike Price